A vacuum heat treatment apparatus, as an apparatus of manufacturing a desired material by heat-treating a raw material in a crucible, has an advantage of preventing pollution from the surroundings from generating by performing a heat treatment in a vacuum state. In the vacuum heat treatment apparatus, a insulating member is positioned in a chamber maintained in the vacuum state and a heat is positioned in the insulating member so as to heat the raw material.
However, a material generated by reacting with the crucible and the raw material during the reaction may be attached on an inner wall of the crucible. Since the generated material is different from the crucible, a heat stress is applied to the crucible due to a difference of heat expansion coefficients between different materials. In a serious case, the crucible may be broken by the heat stress during the reaction. Accordingly, a replacement cost of the crucible is extremely generated, such that productivity may be deteriorated.